1. Technical Field
The present subject matter relates to a device for measuring a vehicle on a roadway.
2. Background Art
The measuring of vehicles is of great importance in particular for establishing the suitability or authorization of the use of a road section, such as a tunnel or a toll road, or of a location, such as a parking space or city territory that is subject to tolls. Vehicles that are too high or too wide are to be stopped in time before tunnels, and usage charges are to be determined in road toll systems or at parking spaces as a function of the vehicle height and/or width. The measuring of a vehicle is to take place largely without interfering with traffic flow, which is to say while driving on the roadway. For this purpose, measuring gantries extending transversely over the roadway are installed, for example, and populated with sensors for vehicle measurement.
If the roadway has only one lane, a vehicle height, for example, can be ascertained by way of light barriers transversely radiating at various heights. As an alternative, an image can first be recorded of a vehicle, and the vehicle can thereupon be measured by way of optical image evaluation. A laser scanner installed on a measuring gantry is known from U.S. Pat. No. 6,304,321 B1, which can project two differently inclined fanned scan beams onto the road surface or vehicle surface by way of a rotating deflection mirror having differently inclined mirror facets. By fanning the laser measuring beams, shadowing effects are created so that the lateral faces of a vehicle facing away from the scanner cannot be detected and consequently not measured.
It is known from US 2004/0008514 A2 to mount a line of individual perpendicularly downwardly radiating transmitter and receiver elements for laser time of flight measurement on a measuring gantry. So as not to interfere with each other, the transceiver elements are sequentially actuated either individually or in groups, which may result in detection gaps for vehicles traveling at high speeds; it is thus not possible to reliably associate various vehicle parts or a trailer with a vehicle.